As a new type of solid light source, white light LED has the advantages of energy-saving, environmental protection, long life, small size and the like, thus it has great application prospects in the fields of lighting and display. There are two types of white light LEDs: the first one is consisted of three LEDs: red, blue, and green; the second one is composed of LED chip and the phosphor powder coated thereon. Because the cost of the first type is high, and the light color thereof is not easy to control, the second type is now widely employed the manufacturing method of the white light LED composed of a blue light LED chip and a yellow phosphor powder which may be excited by blue light is simple, the luminous efficiency of the product is high, thereby it is the preferred product to implementation of white light LED, wherein the yellow phosphor powder is mainly composed of YAG fluorescent powder.
The silicate phosphor powder is also a good yellow phosphor powder. Compared to the YAG phosphor powder, the excitation spectrum of the silicate phosphor powder is wider, and has a better color purity, but this phosphor powder has the problem of low luminous efficiency. However, further improving the luminescent properties of the material is the target of the researchers.